UUID Generator & Validator

How it works

• Generation uses crypto.randomUUID() — the browser’s built-in cryptographically secure random number generator, not Math.random() — to produce RFC 4122 version 4 (random) UUIDs. The odds of two v4 UUIDs colliding are astronomically small (roughly 1 in 2.7×10^18 for a billion generated).
• Validation checks the 8-4-4-4-12 hex-digit format (braces optional) and reads the version nibble and variant bits directly out of the string — it doesn’t check whether the UUID was actually issued by anything, only that it’s well-formed.
• A UUID’s version says how it was generated (1 = timestamp+MAC address, 4 = random, others exist for name-based and other schemes) and its variant says which layout rules its bits follow — RFC 4122 is what essentially everything in the wild uses.

Runs entirely in your browser — nothing generated or pasted here is uploaded, logged, or stored.